Anoxia in the Domanik basin of the Timan–Pechora region

Analysis of the carbon isotopic composition in aryl carotenoid derivatives, including isorenieratene, in bitumen from domanikoid rocks of the sections cropping out along the Chut River revealed that they contain anomalously heavy carbon, which is determined by the formation of these compounds from green sulfur bacteria of the family Chlorobiaceae. These bacteria use the peculiar process of carbon fixing as HCO3 − in the reversed tricarboxilic acid cycle. The fact of hydrosulfuric contamination of the photic water layer in the Domanik basin is confirmed by the plurality of data. Anoxity in shelf water of the middle Frasnian Timan–Pechora basin is evident from lithological features such as, for example, lamination of some rocks and mass death of the fauna.